# Avalanche dynamics in hierarchical fiber bundles

## TL;DR

This paper investigates how hierarchical organization in fiber bundle models influences failure behavior, revealing generally decreased strength but also identifying specific arrangements that enhance robustness.

## Contribution

It introduces a fiber bundle model with hierarchical structure and analyzes its impact on avalanche dynamics and failure strength, highlighting both typical and exceptional behaviors.

## Key findings

- Hierarchical structures tend to lower failure strength.
- Certain hierarchical arrangements can increase failure thresholds.
- The model reveals complex avalanche dynamics influenced by hierarchy.

## Abstract

Heterogeneous materials are often organized in a hierarchical manner, where a basic unit is repeated over multiple scales.The structure then acquires a self-similar pattern. Examples of such structure are found in various biological and synthetic materials. The hierarchical structure can have significant consequences for the failure strength and the mechanical response of such systems. Here we consider a fiber bundle model with hierarchical structure and study the effect of the self-similar arrangement on the avalanche dynamics exhibited by the model during the approach to failure. We show that the failure strength of the model generally decreases in a hierarchical structure, as opposed to the situation where no such hierarchy exists. However, we also report a special arrangement of the hierarchy for which the failure threshold could be substantially above that of a non hierarchical reference structure.